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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
a0439711 DB |
2 | /* |
3 | * Glibc independent futex library for testing kernel functionality. | |
4 | * Shamelessly stolen from Darren Hart <dvhltc@us.ibm.com> | |
5 | * http://git.kernel.org/cgit/linux/kernel/git/dvhart/futextest.git/ | |
6 | */ | |
7 | ||
8 | #ifndef _FUTEX_H | |
9 | #define _FUTEX_H | |
10 | ||
11 | #include <unistd.h> | |
12 | #include <sys/syscall.h> | |
13 | #include <sys/types.h> | |
14 | #include <linux/futex.h> | |
15 | ||
16 | /** | |
17 | * futex() - SYS_futex syscall wrapper | |
18 | * @uaddr: address of first futex | |
19 | * @op: futex op code | |
20 | * @val: typically expected value of uaddr, but varies by op | |
21 | * @timeout: typically an absolute struct timespec (except where noted | |
22 | * otherwise). Overloaded by some ops | |
23 | * @uaddr2: address of second futex for some ops\ | |
24 | * @val3: varies by op | |
25 | * @opflags: flags to be bitwise OR'd with op, such as FUTEX_PRIVATE_FLAG | |
26 | * | |
27 | * futex() is used by all the following futex op wrappers. It can also be | |
28 | * used for misuse and abuse testing. Generally, the specific op wrappers | |
29 | * should be used instead. It is a macro instead of an static inline function as | |
30 | * some of the types over overloaded (timeout is used for nr_requeue for | |
31 | * example). | |
32 | * | |
33 | * These argument descriptions are the defaults for all | |
34 | * like-named arguments in the following wrappers except where noted below. | |
35 | */ | |
36 | #define futex(uaddr, op, val, timeout, uaddr2, val3, opflags) \ | |
37 | syscall(SYS_futex, uaddr, op | opflags, val, timeout, uaddr2, val3) | |
38 | ||
39 | /** | |
40 | * futex_wait() - block on uaddr with optional timeout | |
41 | * @timeout: relative timeout | |
42 | */ | |
43 | static inline int | |
44 | futex_wait(u_int32_t *uaddr, u_int32_t val, struct timespec *timeout, int opflags) | |
45 | { | |
46 | return futex(uaddr, FUTEX_WAIT, val, timeout, NULL, 0, opflags); | |
47 | } | |
48 | ||
27db7830 DB |
49 | /** |
50 | * futex_wake() - wake one or more tasks blocked on uaddr | |
51 | * @nr_wake: wake up to this many tasks | |
52 | */ | |
53 | static inline int | |
54 | futex_wake(u_int32_t *uaddr, int nr_wake, int opflags) | |
55 | { | |
56 | return futex(uaddr, FUTEX_WAKE, nr_wake, NULL, NULL, 0, opflags); | |
57 | } | |
58 | ||
d2f3f5d2 DB |
59 | /** |
60 | * futex_lock_pi() - block on uaddr as a PI mutex | |
d2f3f5d2 DB |
61 | */ |
62 | static inline int | |
73b1794e | 63 | futex_lock_pi(u_int32_t *uaddr, struct timespec *timeout, int opflags) |
d2f3f5d2 | 64 | { |
73b1794e | 65 | return futex(uaddr, FUTEX_LOCK_PI, 0, timeout, NULL, 0, opflags); |
d2f3f5d2 DB |
66 | } |
67 | ||
68 | /** | |
69 | * futex_unlock_pi() - release uaddr as a PI mutex, waking the top waiter | |
70 | */ | |
71 | static inline int | |
72 | futex_unlock_pi(u_int32_t *uaddr, int opflags) | |
73 | { | |
74 | return futex(uaddr, FUTEX_UNLOCK_PI, 0, NULL, NULL, 0, opflags); | |
75 | } | |
76 | ||
0fb298cf DB |
77 | /** |
78 | * futex_cmp_requeue() - requeue tasks from uaddr to uaddr2 | |
79 | * @nr_wake: wake up to this many tasks | |
80 | * @nr_requeue: requeue up to this many tasks | |
81 | */ | |
82 | static inline int | |
83 | futex_cmp_requeue(u_int32_t *uaddr, u_int32_t val, u_int32_t *uaddr2, int nr_wake, | |
84 | int nr_requeue, int opflags) | |
85 | { | |
86 | return futex(uaddr, FUTEX_CMP_REQUEUE, nr_wake, nr_requeue, uaddr2, | |
87 | val, opflags); | |
88 | } | |
a0439711 | 89 | #endif /* _FUTEX_H */ |